Dual Cell MEMS Assembly

• US 20120250897A1
• Filed: 04/27/2011
• Published: 10/04/2012
• Est. Priority Date: 04/02/2011
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman Embedded Audio LLC (Samsung Electronics Co. Ltd.)
• Inventors: Michel, Alan Dean, McAteer, Jeffrey Phillip, Baumhauer, John Charles Jr.
• Granted Patent: US 8,804,982 B2
• Time in Patent Office: Days
• US Class Current: 381/111
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H04R 1/2807 Enclosures comprising vibrating or resonating arrangements for the reduction of undesired resonances or vibrations H04R1/2869
• CPC Class Codes: H04R 1/2876 by means of damping material, e.g. as cladding damping material for tuning desired resonances H04R1/2807, e.g. in vents H04R1/2823, H04R1/2846
• CPC Class Codes: H04R 1/30 Combinations of transducers with horns, e.g. with mechanical matching means , i.e. front-loaded hornshorns in general G10K; transducer enclosures or mountings using a back-loaded horn H04R1/2861; application of horns as guiding means to obtain a predetermined directivity characteristic H04R1/345
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A transducer assembly utilizing at least two MEMS transducers is provided, the transducer assembly preferably defining either an omnidirectional or directional microphone. In addition to at least first and second MEMS transducers, the assembly includes a signal processing circuit electrically connected to the MEMS transducers, a plurality of terminal pads electrically connected to the signal processing circuit, and a transducer enclosure housing the first and second MEMS transducers. The MEMS transducers may be electrically connected to the signal processing circuit using either wire bonds or a flip-chip design. The signal processing circuit may be comprised of either a discrete circuit or an integrated circuit. The first and second MEMS transducers may be electrically connected in series or in parallel to the signal processing circuit. The first and second MEMS transducers may be acoustically coupled in series or in parallel.

Claims

1. A transducer package, comprising:

at least a first MEMS transducer and a second MEMS transducer, wherein said first MEMS transducer is acoustically coupled to said second MEMS transducer;

a signal processing circuit, wherein said first and second MEMS transducers are electrically connected to said signal processing circuit;

a plurality of terminal pads electrically connected to said signal processing circuit;

a transducer enclosure, said transducer enclosure housing said first and second MEMS transducers.

2. The transducer package of claim 1, wherein said first and second MEMS transducers are electrically connected to said signal processing circuit utilizing a plurality of wire bonds.

3. The transducer package of claim 1, wherein said transducer package utilizes a flip-chip design.

4. The transducer package of claim 1, wherein said signal processing circuit is comprised of a discrete circuit.

5. The transducer package of claim 1, wherein said signal processing circuit is comprised of an integrated circuit (IC).

6. The transducer package of claim 5, wherein said transducer enclosure further comprises a substrate and a cover attached to said substrate, wherein said first MEMS transducer, said second MEMS transducer and said signal processing IC are attached to said substrate.

7. The transducer package of claim 6, wherein said cover is fabricated from a material selected from the group consisting of a metal, an electrically conductive plastic, an electrically conductive composite, an electrically non-conductive plastic coated with an electrically conductive material, an electrically non-conductive composite coated with an electrically conductive material, or a composite material that includes both dielectric and conductive material layers.

8. The transducer package of claim 1, wherein said first and second MEMS transducers are electrically connected in series to said signal processing circuit.

9. The transducer package of claim 1, wherein said first and second MEMS transducers are electrically connected in parallel to said signal processing circuit.

10. The transducer package of claim 1, wherein said first and second MEMS transducers are acoustically coupled in series.

11. The transducer package of claim 1, wherein said first and second MEMS transducers are acoustically coupled in parallel.

12. The transducer package of claim 1, wherein said transducer enclosure further comprises a substrate and a cover attached to said substrate, wherein said first and second MEMS transducers are attached to said substrate, wherein said substrate further comprises a first aperture aligned with a first transducer aperture corresponding to said first MEMS transducer, wherein said substrate further comprises a second aperture aligned with a second transducer aperture corresponding to said second MEMS transducer, and wherein a transducer back volume is substantially defined by an inner surface of said cover, said first and second MEMS transducers, and a surface of said substrate.

13. The transducer package of claim 12, further comprising an acoustic separation wall within said transducer enclosure, said acoustic separation wall dividing said transducer back volume into a first back volume corresponding to said first MEMS transducer and a second back volume corresponding to said second MEMS transducer, wherein said first MEMS transducer is electrically combined with said second MEMS transducer out of phase to form a directional microphone.

14. The transducer package of claim 12, wherein said transducer back volume is common to said first and second MEMS transducers, and wherein said first MEMS transducer is electrically combined with said second MEMS transducer in phase to form an omnidirectional microphone.

15. The transducer package of claim 12, wherein said transducer back volume is common to said first and second MEMS transducers, and wherein said first MEMS transducer is electrically combined with said second MEMS transducer out of phase to form a directional microphone.

16. The transducer package of claim 12, wherein said transducer back volume is common to said first and second MEMS transducers, wherein said substrate further comprises a third aperture acoustically coupling said transducer back volume to an ambient acoustic environment, and wherein said first MEMS transducer is electrically combined with said second MEMS transducer in phase to form a directional microphone.

17. The transducer package of claim 12, wherein said transducer back volume is common to said first and second MEMS transducers, wherein said cover further comprises a third aperture acoustically coupling said transducer back volume to an ambient acoustic environment, and wherein said first MEMS transducer is electrically combined with said second MEMS transducer in phase to form a directional microphone.

18. The transducer package of claim 1, wherein said transducer enclosure further comprises at least a first substrate and a second substrate and a cap, wherein said first MEMS transducer is attached to said first substrate and said second MEMS transducer is attached to said second substrate, wherein said first substrate defines an outer substrate and further comprises a first aperture aligned with a first transducer aperture corresponding to said first MEMS transducer, wherein said second MEMS transducer is acoustically coupled in series with said first MEMS transducer, wherein said first MEMS transducer is electrically combined with said second MEMS transducer out of phase, wherein said transducer enclosure defines a first back volume corresponding to said first MEMS transducer and a second back volume corresponding to said second MEMS transducer, and wherein said second substrate further comprises a second aperture aligned with a second transducer aperture corresponding to said second MEMS transducer.

19. The transducer package of claim 1, wherein said first and second MEMS transducers are comprised of a contiguous die pair.